Set BOOTLOADER = stm32-dfu for all applicable STM32 boards (#12956)

* Set bootloader to stm32-dfu for STM32F303

* Set bootloader to stm32-dfu for STM32F0x2

* Set bootloader to stm32-dfu for STM32F4x1

* Set bootloader to stm32duino for sowbug

* Delete redundant bootloader_defs headers

* Add some missing MCU name comments

* Move APM32 dfu-suffix overrides underneath bootloader

* Remove redundant STM32_BOOTLOADER_ADDRESS defines/rules

keyboards/chavdai40/bootloader_defs.h

@@ -1,5 +0,0 @@
-/* Address for jumping to bootloader on STM32 chips. */
-/* It is chip dependent, the correct number can be looked up here:
- * http://www.st.com/web/en/resource/technical/document/application_note/CD00167594.pdf
- */
-#define STM32_BOOTLOADER_ADDRESS 0x1FFFC400

keyboards/chavdai40/rev1/rules.mk

@@ -1,6 +1,9 @@
 # MCU name
 MCU = STM32F042
 
+# Bootloader selection
+BOOTLOADER = stm32-dfu
+
 # Build Options
 #   change yes to no to disable
 BOOTMAGIC_ENABLE = lite     # Virtual DIP switch configuration
@@ -15,4 +18,4 @@ NKRO_ENABLE = no            # USB Nkey Rollover
 BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
 RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
 BLUETOOTH_ENABLE = no       # Enable Bluetooth
-AUDIO_ENABLE = no           # Audio output
+AUDIO_ENABLE = no           # Audio output

keyboards/chavdai40/rev2/rules.mk

@@ -1,6 +1,9 @@
 # MCU name
 MCU = STM32F042
 
+# Bootloader selection
+BOOTLOADER = stm32-dfu
+
 # Build Options
 #   change yes to no to disable
 BOOTMAGIC_ENABLE = lite     # Virtual DIP switch configuration
@@ -15,4 +18,4 @@ NKRO_ENABLE = no            # USB Nkey Rollover
 BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
 RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
 BLUETOOTH_ENABLE = no       # Enable Bluetooth
-AUDIO_ENABLE = no           # Audio output
+AUDIO_ENABLE = no           # Audio output